'Veilchen' (i) was a U-boat wolfpack operation in the Atlantic against the SC.107 slow convoy (24 October/7 November 1942).
Created in an area off the east coast of Newfoundland after the end of the operation against the ON.137 convoy, the wolfpack initially comprised U-71, U-84, U-89, U-132, U-381, U-402, U-438, U-454, U-571, U-658 and U-704, reinforced from 27 October at the southern of its patrol line by U-437 and U-442, and for the loss of Korvettenkapitän Hans Senkel’s U-658 sank eight ships (43,935 tons) and damaged two ships (12,995 tons).
The SC.107 convoy, initially supported by the Western Local Escort Force’s British destroyer Walker and Canadian corvettes Fennel, Cowichan and Timmins, was met to the south-west of Cape Race by feeder convoys from Halifax and Sydney, Nova Scotia, to create a convoy totalling 42 ships supported by Lieutenant Commander D. W. Piers’s Canadian Escort Group C4 (destroyer Restigouche, and corvettes Algoma, Amherst, Arvida, Sherbrooke and British Celandine) bolstered at first by Walker and the Canadian destroyer Columbia; also with the convoy was the HF/DF-equipped rescue ship Stockport.
With its first elements having departed New York City on 24 October, the convoy was bound for Liverpool, and became involved in a battle with the wolfpack between 30 October and 4 November. The convoy was located and reported by Kapitänleutnant Herbert Schneider’s U-522 on 30 October as the Western Local Escort Force passed responsibility for the convoy the Escort Group C4. Kapitänleutnant Volkmar Schwarzkopff’s U-520 missed Walker, but was then sunk near the convoy by a Douglas Digby medium-range patrol bomber of the RCAF’s No. 10 Squadron.
On 31 October U-522 was driven off by a destroyer and U-521 by a Lockheed Hudson medium-range patrol bomber of the RCAF;s No. 145 Squadron. Responding to intelligence provided by the B-Dienst signals intercept and analysis service, Admiral Karl Dönitz, the Befehlshaber der Unterseeboote, had meanwhile shifted the 'Veilchen' (i) wolfpack’s patrol line farther to the south, with the result that the SC.107 convoy was spotted and reported on 1 November by U-381. The first boats to come up were U-381, U-402 and U-704, but these were located by HF/DF and driven off by Celandine and Restigouche. Shortly after sunset U-71 was located by radar and forced to dive, and U-89 missed the convoy.
The U-boat 'ace' Kapitänleutnant Siegfried von Forstner’s U-402 torpedoed and damaged the 7,459-ton British Empire Sunrise, which was later sunk by Kapitänleutnant Horst Uphoff’s U-84, and torpedoed and sank the 4,558-ton British Dalcroy, 4,945-ton British Empire Antelope, 5,676-ton British Empire Leopard and 4,649-ton Greek Rinos after midnight on 1 November. Restigouche outmanoeuvred the attempt by U-381 to torpedo her.
Kapitänleutnant Herbert Schneider’s U-522 then torpedoed and damaged the 5,496-ton British Hartington, which was later despatched by Kapitänleutnant Klaus Bargsten’s U-521, and torpedoed and sank the 5,804-ton British Maratima and 5,655-ton Greek Mount Pelion. U-442's attack was unsuccessful. U-522 also torpedoed and sank the 3,189-ton Greek Parthenon in a daylight attack on 2 November. Some 112 merchant seamen were lost, together with 7,410 tons of zinc concentrate, 8,000 tons of wheat and tanks, 11,809 tons of steel and timber, and 26,330 tons of general cargo including trucks and explosives.
Already reinforced by the arrival of the Canadian corvette Moosejaw, the escort was now further bolstered by the British destroyer Vanessa diverted from the escort of the the HX.213 convoy. As visibility improved, U-71, U-84, U-381, U-402, U-438, U-521, U-522, U-571 and U-704 in turn established contact by day on 3 November because the convoy, after several zigzag manoeuvres, had resumed its base course. An attempt to attack by the contact-keeping U-438 failed, and Celandine and Vanessa drove off other boats located by HF/DF.
At about 12.00 on 3 November, however, Bargsten’s U-521 torpedoed and sank the 6,855-ton US tanker Hahira, but U-522 missed Restigouche. The escorts managed to keep all of the U-boats away from the convoy during the afternoon and early evening, although U-438 was able to attack the detached rescue ship Stockport, though without success. After dark, however, Korvettenkapitän Dietrich Lohmann’s U-89 torpedoed and sank the 5,318-ton British Jeypore, while Korvettenkapitän Ernst Vogelsang’s U-132 torpedoed and sank the 6,379-ton British Empire Lynx and 5,507-ton Dutch Hobbema, and torpedoed and damaged the 6,690-ton British Hatimura, which was later sunk by Korvettenkapitän Hans-Joachim Hesse’s U-442. It is believed that U-132 was destroyed by the huge detonation of this last vessel’s cargo of ammunition. Some 36 merchant seamen were lost, together with 8,985 tons of fuel oil and 21,050 tons of explosives and general cargo. Attacks by U-71, U-438 and U-442 were unsuccessful.
On 4 November Arvida and Celandine were detached to Iceland with the survivor-laden Stockport and the tugs Uncas and Pesaccus similarly overcrowded with 240 survivors. U-89 torpedoed and sank the 4,640-ton British Daleby carrying 8,500 tons of grain shortly before the convoy escort was reinforced by the arrival from Iceland of the cutter Ingham of the US Coast Guard and the destroyers Leary and Schenck of the US Navy.
During the morning of 5 November, U-84, U-381, U-442, U-454, U-521, U-522 and U-571 were still in contact, but were finally driven off by the arrival of Consolidated Liberator long-range patrol bombers of the RAF’s No. 120 Squadron, one of which damaged U-89.
The Germans broke off their operation on the following day, and the convoy’s surviving ships reached Liverpool on 10 November.